Electric system of transmission.



' No. 823,505. PATENTED JUNE 19, 1906.

' '0. G. BURKE.

ELECTRIC SYSTEM OF TRANSMISSION.

ABPLIOATION FILED DEC. 9. 1902.

2 SHEETS-SHEET 1.

Z IINVENTOR ATTORNEY ANDREW. l (mum c0. rnmu-Lmwunvnzpt. WAININGYON, o, C.

No. 823,505. PATENTED JUNE 19, 1906;

c. G. BURKE. v ELECTRIC SYSTEM OF TRANSMISSION.

APPLIOA TION TILED DEC, 9, 1902.

2 SHEETS-SHEET 2.

NVENTOR ANDREW s. GRAHAM 00.. FllOlO-LITHOGRAPNERS. waarmcrcu UNITED STATES PATENT CHARLES e. BURKE, or BROOKLYN, NEW YORK, A ss'IeNoR or ONE-HALF TO JOHN o. A. WHITTEMORE, or BOSTON, MASSACHUSETTS.

E orRIc SYSTEM OF TRANSMISSION.

Specification of Letters Patent.

Application fil d December 9, 1902. Serial No. 134.545.

Patented June 19, 1906,

. following is a specification, reference being 'panying drawings, in whichhad to the accompanying drawings, forming a part hereof.

-My invention relates to electric systems of transmission, and it particularly relates to systems for sending signals from one point to anothen i t g The object of the invention is to provide a system wherein a signal may be produced which has a period corresponding in length to the telegraphic signals. It also has for its object to provide a means for sending signals over a single ungrounded main line. It has a further object .to provide acombined telephonic and telegraphic system. i

. The invention consists in a means for sending signals over a main line and causing areceiving means to be affected for periods of time varying according to the length of the signalsto be sent. v Y

The invention also consists in providing a means for constantly charging themain line of an electric system and then causing the said charging means to operatively aiiect the instruments of the line. The invention alsoconsis'ts in providing a means whereby an electric system may be used as a telephone or as a telegraph system. In order that this may be done, there is pro vided means for readily changing the connections of the instruments to form one system or the other. I

The invention also consists in providing signaling means for use in connection with a single 'ungrounded main line. Such a signal ing means may be used for purposes of teleg- A raphy or it may be used in connection with a telephone systemoperated either ona single ungrounded mainline or acompleted circuit. I The invention also consists in other features and arrangement of devices which appear in the tollowing description and are claimed in the claims.

"The invention is illustrated in the accom- Figure 1 illustrates diagrammatically a the switch 9 is closed.

form of a system whioh embodies my inve'n tion. .Fig. '2 illustrates one of the Ways in which a receiving apparatus may be com nected with the main line in; a system embodying my invention. Fig. '3 illustrates a system wherein the capacity'cf eainth'col'l vv nection is used. Fig. 4 illustrates a com bined telephone system and a. signaling sys= tem. Fig. 5 illustrates a system for sending signals toa plurality of stations from asingle, station.

In Fig. 1 are illustrated the connections be .tween the instruments of two stations ahd the main line connecting the stations to gethen Each station has a receiving appe ratus and a meansfor constantly charging the main line. The means for charging the -main line cooperates with other features of the system to affect the receiving'appamtus,

. and thus constitutes a transmitting means.

The means for constantly charging the main line, as illustrated in Fig. 1, eonsistsof .a local circuit '1, in WlliOh are connected an induction-coil 4 and ameansfor" produeinga pulsating current, suchas a batteryaand the vibrator 5. Any other means,however, may be used for charging the line, such as a en erator of"n alternating current and other (is-- vices known in the art. In the system illnetrated"the" current energizes the magnet 6, which draws the ends' of the tuning-fork 7 together, and the current throughthebaek con tact 8 is broken. The magnetithen releases 5 the end of the tuning-fork land thecireuit is again closed. The oppration repeats itself, causing the tuning-for to vibrate as long as .ducion' coil 4 to pulsations of much higher' potential than that of the battery, because f the larger number of windings of the sec ondary coil 1 1; This is particularly true {ifa vibrator is used to produce pulsation-s on the line, for as the circuit is closedand broken by means of the vibrator the extra-current or what is: known as the electric kick produced in the coils of the local circuit Q1 the time'of breaking ofthe-oircuit reduces-every I highaotentiahwhichis repro' need and mag.-

nifie in the main line.

One terminal of the secondary coil 11 is} sations ofelectricity on theline. If the second directly connected with the main line. One terminal of the receiving apparatus 12 is also directly connected with the main line. The receiving apparatus used in the system illustrated consists of a telephone-receiver. Any receiver, however, may be used that is responsive to currents produced on the main line. The remaining terminals of the secondary coil and the receiving apparatus are connected to contacts associated with a switch or key 13. The terminal of the secondary coil is connected to contact 14 and the terminal of the receiving apparatus is connected to contact 15. The key 13 is nor mally held in contactwith the contact 15 by means of the tension-springusually asso- V ciated with instruments of that character.

The key illustrated is pivoted at its center,

and when the finger end of the key is pressed it is closed upon contact 14. By this arrangement the key is normally in connection -with the receiver and abnormally with the the key 13, and bymeans of the key the condenser is brought into connection either with that other station.

the receiving apparatus or the induction-coil. If a party at one station desires to signal a party at another station, he will start the means for charging the main line leading to In the particular system illustrated he will close the switch 9, which start the vibrator; but inasmuch as the capacity bodythe condenseris not connectedwith the secondary coil the receiving app aratus';at the other end of the line will .not be ,operatively affected.

If then the party about'to signal presses the key the condenserof that station will be connected withthe secondary coil, and the charges produced: on the main line 'through the medium of that v coil will cause pulsations of electricityto flow back and forthm the condensers located at the ends of the line, pulsations will continue to flow as long ES Dll Q'COIldGIlSGI is connected with the charging means. This will produce a very loud soundfin the receiving apparatus, which will continue as long as the key is held down by the party signaling. The quantity of sound thusreduced may be reduced in many ways whic are well-known in the'art. The operation: of thereceiving apparatus will call up the party 'at' t'he distant station, who will then listen to. the signals that are being sent by the first party. As the key is opened and closed by the first party the receiving apparatus of the "listening party is correspondingly affected by pulparty now wishes to answer the first party, he will likewise close switch 9 and open and close the key according to the signals that he may Wish to send. If it is desired, the switches 9 may be kept closed and the tuning-fork kept in constant vibration at all times without in any way operatively interfering with the signaling or the receiving apparatus.

The receiving apparatus may be connected with the line in many ways. Also two receiving apparatuses may be used in a single station. One may be used for calling a party of the station, and another, which may be so regulated to reduce the uantity of sound ordinarily produced, ma e used for listening purposes-that is, for the purpose of receiving the signal proper. One of the ways of connecting a receiving apparatus with the main' line and which magnifies the effect produced in the apparatus is shown in the system illustrated in Fig. 2. In that system a receiver 17 is connected in the local circuit 19, in which is also connected a secondary coil 18. The primary coil 20 of the induction-coil 21 is connected in the main line and has alarger number of turns than the secondary coil 18. The induction-coil thus constitutes a step down transformer. As many local circuits of the typejust described may be located at different points along the main line as desired. The receivin apparatus will in each case receive the pu sations sent over the line.

In Fig. 3 is illustrated a system wherein the capacity of an earth connection may be used. The arrangement is such that the key 13 may be connected either with the earth or the condenser 16. The pivot of the key is connected with a switch 22, which has two eon-' tactscontact 23, which is connected with the earth, and contact 24, which is connected with the condenser 16. It is found that the greater the capacity of the capacity body used in operating the system the louderis the sound produced in the receiving apparatus.

When the keys located at both ends of the line are connected with the earth through the switches 22, a very loud sound is produced in the receiver. So great is this effect on the system that the charging means normally affects the receiver. It is therefore found preferable to use the earth connection at one end of the main line and the condenser at the other end of the main line. The earth connection is preferably used at the transmitting end of the main line and the condenser at the receiving end. In the latter case the switch 22 will normally be connected with the condenser, and when one of the parties wishes to signal the other party the first party will move the switch 22 so as to make connection with the earth.

In Fig. 4 is illustrated a combined teleto make the change in the connections. One arm 26 of the switch is-used to alter the phone and telegraph system embodying my invention. Either the telephone or the telegraph instruments may be placed in condition for use by merely shifting a circuitchanger. The arran ement is such that either the means for c arg'ing the line or the telephone-transmitter may be connected in the local circuit, and a corresponding change may be made in the main line. When an in duction-coil is used to connect the charging means with the main line, the same induction-coil may be used to transform the telephonic currents produced by the transmitter and the battery in the local circuitto the main line. A double pole-switch 25 is used connections of the main line, and'the other arm 27 is used to make the change of connections in the local circuit. Thepivoted end ofthe arm 26 is connected with the-telephone-receiver 12, which is in turn connected with the normal contact of the key 13, and

when the key is in its normal position the receiver is connected with. the condenser 16'.

One contact of the switch=arm 26 is connect ed with one terminal of the secondary 11 of the induction-coil 4-. By this arrangement the receiving apparatus is connected directly with the main line when it is used for the purpose ofsignaling and to the secondaryll of i the-inductioh-coil when itisto be used as a telephone-receiver. Telephonic speech can of course be received and heard if the telephone-receiver is connected directly with the main line inthe sameway that it is connected for telegraphic transmission, and also signals can be received When the receiver is connected with the main linethrough the secondary coil 11. ceiving" apparatus may therefore'be made permanent and independent of the. switch and may be connected either with the main line or with the secondary coil 11; but it is found that better results are obtained connecting the receiver in the manner described. The pivoted end of the other switch-arm 27 is connected with the battery 2., which'is in turn connected with the primary coil 3 ofthe induction-coil 1. The contacts of the switcharm 27 are connected, respectively, with the means for charging the main line for purposes 7 of telegraphy and the telephone-transmitter to be used in the transmission of speech- 55 waves. When the switch-arm 26 makes connection with the main-line instruments for makes corresponding connections in the local circuit for the same purpose. The same is true when'theinstrjuments are to be used for I the purposeof telephony. When the switch 1 i'sin position for 'si'gnaling' pur oses and the l party at one of the stations "esires. to call 7 up'a party at the other station, he may :do so The connection of the reby merely pressing the key 13, which will cause a loud sound to be produced in the receiving apparatus at the other station. The first party may then either continue to signal by code-signaling or he may change the connections by means of the switch 25 and converse with the other party through the telephonicinstruments. This system may also be used to call up a substation in a telephone system. Asimple magnetic vibrator may be used in place, of the tuning-fork, and the switch may be operated by the supportinghook for the telephone-receiver.

In Fig. 5 isillustrated a system embodying my invention and wherein a single local cir- 1 cuit and a single condenser maybe used in connection with a plurality of outgoing lines.

The means for charging the lines may consist of a plurality of induction-coils whose primaries, together with the vibrator 5 and the battery. 2, are connected in the local circuit. As in the systems already described,

the vibrator opens and closes the circuit of the battery2 and causes pulsatingcharges to be produced on the outgoing lines through the mediumof the secondaries of the in The keys are provided with contacts 33,

which are connected together and with the condenser 16. When the key associated with one of the lines is closed, the oscillatory charges produced on thatline by the local circuit are permitted to produce an oscillatory current on the line, the oscillations passing in and out of the condenser 16. The signals arereceived in the manner already described. The invention may be used with many forms of systems of telephony and telegraphy, and the system that I have illustrated may be altered in many ways Without de-' parting from thespirit of my invention.

Some of the advantages of my invention over the systems now known in the .art consist in the fact that the highpotential charges placed upon the main line cause a clear reproduction of thesignal over very long lines of high resistance, and therefore cheaper wires may be used in constructing the line. A single ungrounded main line may be used, thus doing away with either a return-line or completelyobviating the disturbancesdue to earth-currents oommo'n'to systems which depend upon the earth as return connection of the line. A system for the transmission of signals, such as telegraphic signals, may be readily altered into a except for the transmitting means, the same &

instruments that are used in the one case may be used in the other. flowing current is not required in order to keep thesystem in condition to call a distant operator, as is the case in many forms of telegraph systems. The system is always in condition for signaling the distant operator.

The signals produced in the receiving apparatus are exactly of the same period as indicated by the relative lengths of the telegraphic signals. The signals as heard in the receiving means do not consist of mere clicks after periodsoi silence, which periods correspond in length to the telegraphic signals. The line being in a state of constant excitation, the variations produced by the key are instantaneous. The system is therefore adapted to uick signaling. The system either. in the dorm of a telephone or a telegraph system is easily operated with any form of a capacity body.

What I claim, and desire to secure by Letters Patent, is as follows:

1. In a signaling system the combination of a main line, a receiving apparatus, a means for constantly charging the main line, and a capacity body for causing the charging means to affect the receiving apparatus when signals are sent over the line.

2. In an electric system the combination of a main line, a transmitting means for constantly charging the said main line, a receiving apparatus and means for bringing into operative connection with the line either the transmitting means for operatively afi'ecting the main line when signals are set over the line or for connecting the receiving appara tus to the main line.

3. In an electric system the combination of a main line, a transmitting means for constantly charging the said main line, a receiving apparatus, a means for causing the said transmitting means to operatively affect the said main line and for permitting the receiving apparatus to be operatively affected by charges on the line when signals are sent.

4. In a signaling system the combination of a main line, means for constantly charging the said main line, receiving apparatuses located at different points along the said main line, and means for causing the said charging means to'affect one of the said receiving apparatuses and to permit another of the said receiving apparatuses to be afiected when signals are sent.

5, In an electric system the combination of a main line, a transmitting means and a receiving apparatus connected to the main line, a capacity body, and means for connecting the said capacity body with the said transmitting means or the said receiving apparatus and thereby connecting the said transmitting means or the said receiving a paratus in series with the said capacity body.

A constantly- 6. I11 an electric system the combination of a main line, means for constantly charging the said main line, a receiving apparatus, a capacity body, and means for connecting the capacity body to the main line either through the charging means or the receiving apparatus.

7. In an electric system the combination of a main line, means for constantly charging the line with pulsating charges, a receiving apparatus, a capacity body, a means for connecting the said capacity body with the said charging means and thereby aiiecting the said receiving means during the period that the capacity body is so connected.

8. In an electric system the combination of a main line, a transmitting means for constantly charging the said main line, a )lurality of receiving devices, a capacity bo y, and means for connecting the said capacity body with the said transmitting means so as to affect the said receiving devices when signals are to be sent.

9. In an electric system the combination of a main line, a telephone transmitter and receiver, a means for constantly charging the said main line, a switch adapted to connect either the said telephone-transmitter or the said charging means in a local circuit, a ca- ,pacity body, and means for connecting the said capacity body to the said main line either through the said charging means or through the said receiver.

10. In an electric system the combination of a main line, a transmitting means, areceiving apparatus, a condenser, an earth connection, and means for bringing the said transmitting means or the said receiving apparatus into connection either with the said earth connection or the said capacity body.

11. In a signaling system the combination of a main line, a local circuit, a primary coil, a means connected in the said local circuit for producing a pulsating current, a secondary coil and a receiver connected to the said main line, a capacity body normally connected to the said receiver for ermitting the receiver to be affected by c iarges in the said main line and a key for connecting the said capacity body with the said secondary coil and disconnecting the said capacity body from the said receiver.

12. In an electric system the combination of a single ungrounded main line, a telephone transmitter and receiver, a signaling means, a capacity body, and a means for connecting either the said receiving means or the said signaling means with the said main line.

13. In an electric system the combination of a main line, a receiving apparatus and a means for charging the said main line, the said receiving apparatus and the said charging means being connected to the said main line, a capacity body and a key normally connectingthe said capacity body to the said name to this specification in the presence of main line through tlliehreceiving appalatlills two SflbSOIibiIlg Witnesses. and adapted to brea t e connection 0 .t e 4 capacity body to the receiving a paratus CHARLES iand to connect the said capacity b0 y to the Witnesses:

main line through the said charging means. F. F. CR AMPii oN, In testimony whereof I have 'signed my I EDWIN SEGER. 

